This application claims priority from United Kingdom Patent Application No. 01 21 393.3, filed Sep. 5, 2001, the entire disclosure of which is incorporated herein by reference.
The present invention relates to keyboards and, more particularly, to a computer keyboard having pressure sensitive keys that sense the force applied on certain keys and produce a change in function or application based on the sensed force applied thereon including navigation key functionality and automatic case shifting functionality.
Embodiments of the present invention are directed to a computer keyboard having a key sensing device that provides two or more levels of sensing by generating electrical signals depending on the force applied on the keys. The different levels of key sensing can be used to provide different functions, for instance, in a software application. This key sensing functionality can be provided on all or only some of the keys of the keyboard. In one example, the key sensing feature is provided on the four scrolling keys to provide different scrolling speeds. When the force applied on a scroll key is small or normal, the scrolling occurs at a normal speed. When the force applied on the scroll key is large, the scrolling occurs at a higher speed. In other examples, the different pressure levels applied on the key can be used to control cursor movement and to produce pressure-based shifting between lower case and upper case.
In accordance with an aspect of the present invention, a method of providing pressure sensitive key functionalities for a keyboard comprises producing a signal by applying a pressure to a key which is configured to produce different signals in response to different pressure levels applied to the key. A user interface response is generated based on the signal produced by the pressure applied to the key. The different signals are adapted to generate different user interface responses for the key.
In some embodiments, the signal corresponds to a frequency of key repeats for the key. An increase in pressure produces a signal corresponding to a higher frequency of key repeats. The key may be a scroll key, and an increase in pressure produces a signal corresponding to an increase in scrolling speed. A low-pressure signal is produced by a pressure below a preset pressure and a high-pressure signal is produced by a pressure at or above a preset pressure. The low-pressure signal generates line scrolling and the high-pressure signal generates page scrolling. Alternatively, in embodiments where more than two levels of pressure can be sensed, a low pressure signal generates low speed scrolling, and successive higher pressure readings generate correspondingly higher speed scrolling actions.
In some embodiments, a low-pressure signal is produced by a low pressure below a preset pressure and a high-pressure signal is produced by a high pressure at or above a preset pressure. The key may be a cursor key, and the low-pressure signal generates a single letter cursor movement and the high-pressure signal generates a single word cursor movement. The low-pressure signal may generate a lower case character of the key and the high-pressure signal may generate an upper case character of the key. The low-pressure signal may generate a first character of the key and the high-pressure signal may generate a second character of the key.
In accordance with another aspect of the present invention, a method of providing pressure sensitive key functionalities for a keyboard, comprises producing a signal by applying a pressure to a key which is configured to produce different signals in response to different pressure levels applied to the key. A low-pressure signal is produced by a low pressure below a preset pressure and a high-pressure signal is produced by a high pressure at or above a preset pressure. The method further comprises generating a user interface response based on the signal produced by the pressure applied to the key. The different signals are adapted to generate different user interface responses for the key.
In some embodiments, the signal corresponds to a frequency of key repeats for the key, an increase in pressure producing a signal corresponding to a higher frequency of key repeats. The key may be a scroll key, and an increase in pressure produces a signal corresponding to an increase in scrolling speed. In other embodiments, the low-pressure signal generates line scrolling and the high-pressure signal generates page scrolling.
In specific embodiments, the key is a cursor key, and wherein the low-pressure signal generates a single letter cursor movement and the high-pressure signal generates a single word cursor movement. In other embodiments, the low-pressure signal generates a lower case character of the key and the high-pressure signal generates an upper case character of the key. The low-pressure signal may generate a first character of the key and the high-pressure signal may generate a second character of the key.
In some embodiments, the key is a cursor control key, and wherein the low-pressure signal generates cursor movement at a slow speed and the high-pressure signal generates cursor movement at a high speed which is higher than the slow speed.